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I recently picked up an L92 with a DOD / VVT delete and decided to tear it down after finding some glitter in the oil, wear on the camshaft & lifters, as well as some metal shards under the valve covers. To my surprise the main bearings, rod bearings, and cam bearings all looked OK but the lifters had some vertical scoring on the roller and the camshaft lobes had seen better days. As I tore into the motor I found these little metal shards under the valley cover, in the oil pan and pickup, and next to the valve springs and oil return gallies. Any help identifying where these cam from would be greatly appreciated!
Here is an overview and my working theory. Please comment if you think this makes sense or if I should check anywhere else. The motor is torn down to the bare block at this point.
Issues
Glitter / Metallic Flakes and smaller scraps found in oil pan + oil pickup
Metal shards (see photo) found in under valve covers near valve springs and oil return holes + under valley cover
Vertical scoring on cam and lifter roller
Inspection
Cam Bearings - Some install wear but look newer
Rod Bearings - No unusual wear
Main Bearings - no usual wear
Pistons - All rings and ring lands account for. Some vertical scoring on piston skirt thrust axis showing signs of contamination in oil
Dual Valve Springs & Ti Retainers - Some wear on the bottom of the retainer where it meets the spring, but nothing matches to the shards
Valve Stem Seals - Wear on the lower 'hat' portion
Theory
The previous owner installed dual valve springs with OEM 1 piece valve stem seals leading to excess wear on the larger OD of the valve steam seal 'hat'
Setup
L92 - Stock Bottom End
LS3 Intake, DOD / AFM / VVT Delete, LS3 Valley Cover
Comp Cam Kit with Dual Valve Springs, Titanium Retainers, 7.4" Push Rods, Trunnion Upgrade Kit
Pictures LS7 Lifter - Vertical scoring (matching cam lobe wear) Metal Shards found under valve cover Metal Shards found under valley cover Metal Shards found under valve cover Dual Valve Spring with OEM Valve Steam Seal showing wear on lower hat. (These valve stem seals are smooth but show wear). Dual valve spring interferes with hat at rest, but once installed seats on lowest seal face
My guess is those pieces are from the rocker arm bearings / trunnions. Somebody did not get their rocker arm to springs to lifter geometry / push rod lengths correctly thought out. This put too much strain on the bearings and now they are in pieces.
My guess is those pieces are from the rocker arm bearings / trunnions. Somebody did not get their rocker arm to springs to lifter geometry / push rod lengths correctly thought out. This put too much strain on the bearings and now they are in pieces.
Rick
Good point, I haven't disassembled the rockers that have the Comp trunnion needle upgrade but that will be next.
Good point, I haven't disassembled the rockers that have the Comp trunnion needle upgrade but that will be next.
I appreciate the recommendation @B52bombardier1 and it looks like you are correct! This is the first rocker that I checked out this morning (#1 cyl intake) and it has a broken trunnion. I need to get these all pressed out and see what the real extent of the damage is.
Some final pics of the carnage to close this thread out. I appreciate the advise and I've decided to go with CHE Trunnions with Bronze Bushings for this next build. For those that know, are the rockers below OK to use with the slight wear on the valve spring side? I know I'll need to check the ID of the bearing journal as well.
The rockers with the trunnions and bearings removed Left - Comp Cam Trunnions, Middle - Bearings with Race in tact, Right - broken race bearings Comp Cam Trunnions with wear on bearing journal and rail seat Bearings with broken races Bearings in tact Lifter Rollers
The rockers look OK. I think I'd replace the damaged trunnions. Looks like a little more than half are still OK. Good used (junkyard) would be OK if they fit & match, better than those anyway. Not sure how it's possible for there to be wear on the rail mating surface since that's not supposed to ever move, and the rail is only aluminum.
Is there any correlation between worn trunnions and failed bearings?
shocked...shocked I tell you to see a Comp Cams trunion kit that has taken out a motor...utterly shocked...
Rockers look fine. You could very lightly polish the tip of the rocker with some metal polish, but thats basically what they look like with any kind of use.
I recently picked up an L92 with a DOD / VVT delete and decided to tear it down after finding some glitter in the oil, wear on the camshaft & lifters, as well as some metal shards under the valve covers. To my surprise the main bearings, rod bearings, and cam bearings all looked OK but the lifters had some vertical scoring on the roller and the camshaft lobes had seen better days. As I tore into the motor I found these little metal shards under the valley cover, in the oil pan and pickup, and next to the valve springs and oil return gallies. Any help identifying where these cam from would be greatly appreciated!
Here is an overview and my working theory. Please comment if you think this makes sense or if I should check anywhere else. The motor is torn down to the bare block at this point.
Issues
Glitter / Metallic Flakes and smaller scraps found in oil pan + oil pickup
Metal shards (see photo) found in under valve covers near valve springs and oil return holes + under valley cover
Vertical scoring on cam and lifter roller
Inspection
Cam Bearings - Some install wear but look newer
Rod Bearings - No unusual wear
Main Bearings - no usual wear
Pistons - All rings and ring lands account for. Some vertical scoring on piston skirt thrust axis showing signs of contamination in oil
Dual Valve Springs & Ti Retainers - Some wear on the bottom of the retainer where it meets the spring, but nothing matches to the shards
Valve Stem Seals - Wear on the lower 'hat' portion
Theory
The previous owner installed dual valve springs with OEM 1 piece valve stem seals leading to excess wear on the larger OD of the valve steam seal 'hat'
Setup
L92 - Stock Bottom End
LS3 Intake, DOD / AFM / VVT Delete, LS3 Valley Cover
Comp Cam Kit with Dual Valve Springs, Titanium Retainers, 7.4" Push Rods, Trunnion Upgrade Kit
Pictures LS7 Lifter - Vertical scoring (matching cam lobe wear) Metal Shards found under valve cover Metal Shards found under valley cover Metal Shards found under valve cover Dual Valve Spring with OEM Valve Steam Seal showing wear on lower hat. (These valve stem seals are smooth but show wear). Dual valve spring interferes with hat at rest, but once installed seats on lowest seal face
After I blew up some of your pics, I realized they looked a lot like what I went through a few years back. I just knew you ran the Comp trunnion "upgrade," even before I read about your mods. I think all your shrapnel and roller wheel scoring can be traced back to that Comp kit. I still cant believe Comp sold a kit that bad. Unbelievable....
Remember the lifters have a max spring pressure rating. I say this because I don’t know what your plans are for lifters. I’d be weary of reusing the lifters as they might have debris in them. At least disassemble and clean them.
Those springs are over kill. Above the spec that BTR says the cam requires. Max is 150lbs . Those spring are 155 lbs installed. With a .600” lift cam the .625” spring makes more sense.
125lbs is more than enough seat pressure. The guy the built it first was wrong.
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Metal Shards throughout L92 - Source? 
